HI I bought a 51 plate ford galaxy only 3 weeks ago and has been in garage ever since with no joy, Water bottle that holds coolent on max when car cold but when going for short drive i check it and no coolent in bottle, car drives fine only thing is heaters blow out cold air when doing 60mph for about 20 mins, we have replced thermostat, radiator and cambelt and new water pump only fitted 6 months ago, also noleaks in system and head gaskette been ckecked and all is fine. Hope someone can help?